RETAINING CONSTRUCTION OF WATCHBAND

Abstract: Secured to the inside of an upper plate (1) is a storage member (15) which contains an operation plate (19) provided with an engagement (21) and springs. An intermediate plate (16) and a rammer (6) are mounted to an end of the upper plate (1), and a lower plate (18) having a band mounting portion and an engaging projection (23) is mounted to an end of the intermediate plate (16). A first band member having an adjustment hole is inserted into a gap between the upper plate (1) and the storage member (15) such that the rammer (6) is inserted into the adjustment hole for an adjustment of a length and engagement. In addition, a second band member is mounted to the band mounting portion to constitute the band.

Description: The present invention relates to a buckle for watch bands. More specifically, the invention relates to a buckle according to the preamble of claim 1. Fig. 10 shows a perspective view of a conventional buckle connected to one of the watch bands 10. It comprises a frame 20 and a tongue 40. An end of the other band 30 is inserted into the frame 20 from the underside of the buckle. The band 30 is pulled in the reverse direction at the frame 20. The tongue 40 is engaged with one of adjusting holes 30a of the band 30 at a desired length. Thus, the length of the band is easily adjustable and the band is worn in good feeling. However, in such a conventional buckle, the band must be attentively inserted in the frame of the buckle from the underside thereof. Otherwise, the buckle may disengage, and the watch may drop. Furthermore, the frame and the tongue rub the surface of the band, causing it to hurt and the life of the band to shorten. Japanese Utility Model Application Laid-open No. 3-127519 discloses a buckle which may eliminate the above mentioned defects. As shown in Figs. 11 and 12, the buckle comprises a rectangular frame 31 in which a first band 42 having a plurality of engaging holes 44 is inserted, a middle plate 46 rotatably connected to an end of the frame, and a bottom plate 48 rotatably connected to the middle plate and a second band 50. The frame 31 has an inner space approximately equal to the thickness of the first band 42. An end of the middle plate 46 is connected to a connecting portion 34 secured to the underside of the frame 31 with a pin 32. A tongue 36 is fixed to the pin 32 to be rotatably supported by the connecting portion 34, and engaged with one of the engaging holes 44 of the first band 42. The middle plate 46 further has an engaging recess 46a to be engaged with an engaging portion 56 provided on the bottom plate 48. The second band 50 is connected to an end of the bottom plate 48 through a connecting link 52. In order to use the buckle, the first band 42 is inserted into the frame 31 and the tongue 36 is rotated and inserted into one of the holes 44 of the band at a preferable length so that the band 42 is secured in the frame 31. The frame 31 is pressed against the bottom plate 48 so that the recess 46a of the middle plate 46 engages with the engaging portion 56 of the bottom plate 48. If a tension is exerted on the band 42 for expanding the band, the tongue 36 is abutted on a side 46b of the middle plate 46, thereby preventing the band from expanding. In order to disengage the buckle, the frame 31 is picked up and pulled up from the bottom plate 48. Thus, the middle plate is disengaged from the bottom plate 48, so that the ring formed by the bands 42 and 53 is expanded. Therefore, the watch can be removed from the wrist. In the buckle, since the effective length of the band is adjusted once to a desired length, the band is not rubbed by the tongue. Thus, the band is not hurt. However, it is not easy to pick up the frame 31 from the bottom plate with fingers because of the thin frame. A buckle as mentioned at the beginning is known from CH-A5-665 536. This buckle has a cover rotatably connected to a plate. Moreover, it has a tongue for engagement with a band. If this band is pulled because the band or the watch is caught on something, the cover will rotate in one direction together with the tongue. As a result, the catch will open and the watch will drop to the ground. Accordingly, the technical problem underlying the present invention is to provide a buckle that can be opened quickly, allows easy length adjustment without scratching the band and still provides a highly reliable safety catch preventing the buckle from being opened in unwanted situations. This technical problem is solved by a buckle according to claim 1. As, according to the invention, the length of the band is adjusted only when required, its lifetime can be increased significantly compared with a band according to the prior art shown in figures 10 to 12. Moreover, band adjustment can be carried out easily without using a separate tool. Furthermore, because of the particular arrangement of the cover and tongue, the cover is prevented from rotation when the band is pulled to the left in figure 3 because the band or watch is caught on something. The reason for this is that the cover and middle plate are rotatably connected while the cover is also secured to the bottom plate by the buckle locking device. Therefore, if the first band member 8 is pulled to the left in figure 3, the cover is not rotated even though the tongue might be rotated to a slight degree. Consequently, unwanted opening of the buckle can be prevented and the band member does not remove itself from the buckle, thus resulting in a highly reliable safety catch. When the cover is pressed against the bottom plate, the engaging projection engaged with the slants to urge the push plates inwardly. The engaging projection passes the slants to be engaged with the engaging projections of the push plates so that the buckle is coupled. By pushing the push plates at the same time, the engaging portion is disengaged from the engaging projection to disengage the buckle. Further advantagous embodiments are laid down in the subclaims. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is an exploded perspective view showing a buckle for watch bands according to the present invention; Fig. 2 is a sectional plan view of the buckle; Fig. 3 is a sectional side view of the buckle taken along a line III-III of Fig. 2; Fig. 4 is a side view showing a buckle of a second embodiment in an opening state; Fig. 5 is a sectional plan view of the buckle of Fig. 4; Fig. 6 is a sectional side view of the buckle taken along a line VI-VI of Fig. 5; Fig. 7 is a sectional view of the buckle taken along a line VII-VII of Fig. 5; Fig. 8 is an exploded perspective view showing a buckle of a third embodiment; Fig. 9 is a sectional view of the buckle of Fig. 8; Fig. 10 is a perspective view showing a conventional buckle; Fig. 11 is a perspective view showing a main part of another conventional buckle; and Fig. 12 is a perspective view of the conventional buckle. BEST MODE FOR EMBODYING THE INVENTION An embodiment of the present invention will be described hereinafter in detail with reference to the accompanying drawings. Fig. 1 is an exploded perspective view showing a buckle for watch bands according to the present invention, Fig. 2 is a sectional plan view of the buckle, and Fig. 3 is a sectional view of the buckle taken along a line III-III of Fig. 2. Referring to Figs. 1 to 3, a triple-fold type buckle of the present invention comprises a cover 1 connected to a first watch band 8 having a plurality of adjusting holes 8b, a bottom plate 7 connected to a second watch band 9, and a middle plate 5 connected to the cover 1 and the bottom plate 7. The cover 1 comprises a pair of side plates 11 integrated therewith. Each side plate 11 has a rectangular opening 1a formed at an end portion thereof, and a pin hole 1b formed at another end portion. The side plate 11 has a sufficient height to form a space for supporting the first band 8 in the cover. A hollow guide housing 4 is disposed inside the cover 1 corresponding to the opening 1a of the side plates 11. The guide housing 4 has a pair of openings 4a at opposite ends thereof, and a pair of notches 4b each of which is formed at one of the corners thereof by cutting the upper and lower plates of the housing. A pair of push plates 2 are slidably mounted in the space of the housing 4 so as to be moved in the lateral direction of the band. The push plates 9 are the same in configuration and are symmetrically disposed in the housing 4. Each push plate 2 comprises a manipulating lug 2b projected from the opening 1a of the cover 1 through the opening 4a, an engaging projection 2a outwardly projected, and a notch 2c formed to be engaged with a return spring 3 so as to urge the push plate 2 outwardly. The engaging projection 2a has a slant 2e formed on the underside thereof. The middle plate 5 is formed to be curved so as to fit a wrist of a wearer and comprises a pair of rounded portions 5a and 5b provided at both ends thereof, respectively. The rounded portions 5a are engaged with a spring-loaded pin 12 or a pin, and the rounded portions 5b are engaged with a pin 13 or a spring-loaded pin. Between the rounded portions 5a, a tongue 6 is inserted. The tongue 6 has a cylindrical base 6a rotatably mounted on the spring-loaded pin 12. The tongue 6 is rotatable in the clockwise direction at a position shown in Fig. 3 and prevented from rotating in the counterclockwise direction by a stopper (not shown). Consequently, as shown in Fig. 3, when the tongue 6 is engaged with the adjusting hole 8b of the first band 8, the first band 8 can not be moved in the left, preventing the band from loosening. The middle plate 5 is further provided with a pair of notches 5c formed on both sides corresponding to the notches 4b of the housing 4. The bottom plate 7 is curved along the middle plate 5. The bottom plate 7 has a pair of connecting lugs 7a each having a hole provided at one of ends and formed by bending each side toward the cover for connecting a second watch band 9 and a rounded portion 7c provided at the other end. A pair of engaging lugs 7b each having an engaging hole 7d are formed on both sides of the bottom plate corresponding to the notches 5c of the middle plate 5. The engaging hole 7d is engaged with the engaging projection 2a of the push plate 2. The assembling of the buckle will be described. The return spring 3 is disposed between the notches 2c of the opposite push plates 2 as shown in Fig. 2, and the unit of the push plates is inserted into the housing 4 from one of the openings 4a. Thereafter, a pair of pins 4c are inserted into holes 4d formed in the housing 4 with force and engaged with elongated holes 2d formed in the push plates 2. The push plate 2 is located in the housing 4 by the pin 4c at a position where the manipulating lug 2b is projected from the opening 4a. Consequently, the push plates 2 are prevented from removing from the housing 4. In this state, the engaging projections 2a are exposed in the notches 4b of the housing 4. The assembled housing 4 is disposed inside the cover 1 and the manipulating lugs 2b of the push plates 2 are projected from the openings 1a of the side plates 11 so that the housing 4 is secured to the cover 1. Both ends of the spring-loaded pin 12 engaged with the rounded portions 5a of the middle plate 5 and the tongue 6 are inserted into pin holes 1b formed in the side plates 11 of the cover 1. Thus, the middle plate 5 is rotatably connected to the cover 1. The rounded portion 7c of the bottom plate 7 is connected to the rounded portions 5b of the middle plate 5 with the pin 13 so that the middle plate 5 is rotatably connected to the bottom plate 7. The first and second bands 8 and 9 are connected to a watch case (not shown) at respective connecting portions 8a and 9a. The second band 9 is connected to the connecting lugs 7a by a spring-loaded pin 14 or a pin. Thus, the assembling is completed. The first band 8 is secured to the cover 1 by a wearer. Namely, the end of the first band 8 is inserted into the space between the cover 1 and the housing 4 from the left of the cover (Fig. 3). The tongue 6 is pushed by the band 8 to be rotated in the clockwise direction in Fig. 3 so that the band passes over the tongue 6. The tongue 6 is engaged with the desired adjusting hole 8b corresponding to the size of the wrist. Thus, the first band 8 is connected to the cover 1. The use of the buckle will be described hereinafter. Assuming that the lock of the buckle is released, the middle plate 5 connected to the cover 1 is rotated about the pin 13 to open from the bottom plate 7. The cover 1 is rotated about the spring-loaded pin 12 to open from the middle plate 5 so that the buckle are stretched and expanded. The first and second bands 8 and 9 are applied to the wrist of the wearer. The cover 1 is put on the middle plate 5 and pressed against the bottom plate 7 together with the middle plate 5. The engaging lugs 7b of the bottom plate 7 are inserted into the notches 5c of the middle plate 5 and inserted into the notches 4b of the housing 4. The slants 2e of the engaging projections 2a of the respective push plates 2 are abutted on the engaging lugs 7b, so that the push plates 2 are inwardly pushed against the elastic force of the spring 3. When each engaging projection 2a passes the upper edge of each engaging lug 7b, the engaging projection 2a is returned by the spring 3 and engaged with the engaging hole 7d of the engaging lug 7b. Thus, the cover 1 is locked to the bottom plate 7. In order to unlock the buckle, the manipulating lugs 2b of the push plates 2 are pushed at the same time so that the engaging projections 2a are disengaged from the engaging lugs 7b. Thus, the cover 1 is released from the bottom plate 7. Figs. 4 to 7 show a buckle of the second embodiment. The parts which are the same as the first embodiment are identified with the same reference numerals as Figs. 1 to 3. In the second embodiment, a hollow guide housing 15 has engaging holes 15a formed in upper and lower plates thereof corresponding to each other and penetrating through the center of each plate. A pair of push plates 19 slidably mounted in the space of the housing 15 are the same in configuration and disposed in point symmetry with respect to the center of the housing 15. Each push plate 19 comprises an engaging hook 21 having a downward slant 21a formed underside thereof (Figs. 6 and 7). The engaging hooks 21 are disposed opposite to each other and provided corresponding to the engaging holes 15a of the housing 15. Between the push plates 19, a pair of return springs 22 are provided on both sides with respect to the longitudinal direction and disposed in point symmetry so as to outwardly urge the push plates 19. The push plate 19 has a width wider than a manipulating lug 19b. When the push plates 19 are outwardly urged by the return springs 22 and the manipulating lugs 19b are projected from the openings 1a of the cover 1, both shoulder portions of the push plates 19 are abutted on inner peripheries of the cover 1, thereby preventing the push plates 19 from removing from the cover 1. As an alternative manner for preventing the push plate from removing from the housing 15, a periphery of an opening of the housing is inwardly bent to be engaged with the shoulder portions of the push plate. In the embodiment, a middle plate 16 and a bottom plate 18 are made of metal plate by machining. The middle plate 16 is formed to be curved so as to fit the wrist of the wearer. The middle plate 16 comprises a rectangular frame 16a having a large thickness, a pair of connecting lugs 16b projected from an end of the frame 16a, a pair of arm portions 17 projected from the other end of the frame 16a opposite to the connecting lugs 16b and having a small thickness, and a pair of connecting lugs 17a formed at ends of the arm portions 17. A spring-loaded pin 17b or a pin is engaged with the connecting lugs 17a, and the tongue 6 is rotatably mounted on the pin 17b between the connecting lugs. Both ends of the pin 17b are inserted into the pin holes 1b of the cover 1 so that the cover 1 is rotatably connected to the middle plate 16. The bottom of the housing 15 is mounted on the arm portions 17 of the middle plate 16 (Fig. 7). The bottom plate 18 has a width so as to be engaged with the inside of the middle plate 16. The bottom plate comprises a thick plate portion 18a engaged in the frame 16a of the middle plate, a thin plate portion 18b engaged with the arm portions 17, and an engaging lug 23 securely mounted on the thin plate portion 18b at the center thereof. The engaging lug 23 has a conical head 23a corresponding to the engaging holes 15a of the housing 15. The bottom plate 18 has rounded connecting portions 18c and 18d provided at both ends thereof. The connecting portion 18c is rotatably connected to the connecting lugs 16b of the middle plate 16 with a pin 16c or a spring-loaded pin. The connecting portion 18d is rotatably connected to a connecting link 24 with a pin 24a or a spring-loaded pin to which an end of the second band 9 is connected. In the case that it is undesirable to provide the engaging hole 15a in the upper plate of the housing 15, a recess is formed on an upper portion of the engaging hook 21 so as to receive the conical head 23a. Describing the use of the buckle, the cover 1 is mounted on the arm portions 17 of the middle plate 16, and the cover 1 is pressed against the bottom plate 18 so that the frame 16a engages with the thick plate portion 18a and the arm portions 17 engage with the thin plate portion 18b. The engaging lug 23 of the bottom plate 18 is inserted into the hole 15a of the lower plate of the housing 15. The conical head 23a of the engaging lug 23 engages with the downward slants 21a of the engaging hooks 21 of the respective push plates 19 to outwardly push the engaging hooks against the elastic forces of the springs 22. When the conical head 23a passes the engaging hooks 21, the engaging hooks are returned by the springs 22 and engaged with a stem of the engaging lug 23. Thus, the cover 1 is locked to the bottom plate 18. In order to disengage the buckle, the push plates 19 are pushed at the same time so that the engaging hooks 21 are opened to disengage the engaging lug 23. Figs. 8 and 9 show a buckle of the third embodiment. The third embodiment has a feature that a middle plate 26 and a bottom plate 27 are made by the press working. In the cover 1, the housing 15 having a pair of push plates 19 and return springs (not shown) which are the same as the second embodiment are disposed. The middle plate 26 has a pair of rounded portions 26a and a rounded portion 26b which are provided at both ends thereof, and a rectangular opening 26c formed corresponding to the engaging holes 15a of the housing 15. The tongue 6 and the rounded portions 26a are rotatably connected to the cover 1 with the spring-loaded pin 12. The bottom plate 27 comprises opposite side flanges 27a, a pair of connecting lugs 27b provided at one of the ends, each having a hole, and a pair of rounded portions 27c provided at the other end. The bottom plate 27 further has an engaging projection 28 having a T-shape formed by cutting and bending the plate. The engaging projection 28 has guide slants 28a formed on a top portion thereof opposite to each other, and hooks 28b formed on the lower portions of the guide slants 28b. The rounded portion 26b of the middle plate 26 is rotatably connected to the rounded portions 27c of the bottom plate 27 with the pin 13. The second band 9 is connected to the connecting lugs 27b with the spring-loaded pin 14. The use of the buckle will be described. The cover 1 put on the middle plate 26 is pressed against the bottom plate 27 so that the middle plate 26 engages with the side flanges 27a of the bottom plate 27. As shown in Fig. 9, the top of the engaging projection 28 of the bottom plate 27 passes the hole 15a of the lower plate of the housing 15 and is inserted between the engaging hooks 21 of the push plates 19. The push plates 19 are inwardly pushed by the guide slants 28a of the engaging projection 28 against the elastic force of the springs. When the slants 28a pass the engaging hooks 21, the engaging hooks 21 are returned by the springs and engaged with hooks 28b of the engaging projection 28. Thus, the cover 1 is locked to the bottom plate 27. PROBABILITY OF INDUSTRIAL EXPLOITATION In accordance with the present invention, if the length of the band is adjusted once, it is not necessary to adjust the length when the watch is put on the wrist. Consequently, the surface of the band is not hurt. Since the first band is connected to the second band through the buckle, there is no danger of dropping the watch when putting on and taking off it. By pushing the push plates at the same time, the buckle is easily disengaged.

Claims: A buckle for watch bands having a first band member (8) having a plurality of adjusting holes and a second band member (9), the buckle having a longitudinal first end side and a longitudinal second end side, and including a cover (1) having opposite side plates (11), a middle plate (5;16;26) rotatably connected to said cover (1) at a longitudinal first end thereof by a pin (12), and a bottom plate (7;18;27) rotatably connected to a second end of said middle plate (5;16;26) at a longitudinal end(s) thereof, by a pin (13), characterized in that the cover (1) is rotatably connected to the middle plate (5;16;26) at a longitudinal first end of the first end side, and has opposite openings (1a) formed in the side plates (11) at a longitudinal second end which is located at an inner side toward the second end side of the buckle; a tongue (6) is rotatably mounted on the first end of the cover (1) by the pin (12) to be engaged with one of the adjusting holes of the first band member (8); a guide housing (4;15) is disposed in an inside of said cover at a position corresponding to the openings (1a); a space is formed between an upper plate of the guide housing (4) and an inside wall of the cover (1) in which the first band member (8) is inserted and supported; a pair of push plates (2;19) are slidably mounted in said guide housing (4) so as to be slid in the lateral direction with respect to the longitudinal direction of the bands; a spring (3;22) is provided between the push plates (2;19) for outwardly urging the push plates respectively; stopping means (4c) is provided for stopping each of the push plates at a position where an outer end portion (2b) of the push plate is projected from said openings (1a) of the side plate (11) of the cover so as to be operated by a finger of a wearer; each push plate has an engaging projection (2a, 21) and a slant (2e, 21a) formed on the underside of the engaging projection; at least one engaging lug (7b, 7d; 23, 28) is formed on said bottom plate (7;18;27) to be projected to the push plates (2;19), the engaging lug is arranged such that a part of the lug is engaged with said slant of the push plate so as to inwardly move the push plate due to the inclination of the slant when the bottom plate is pivoted toward the cover, and that the engaging lug engages with the engaging projection when passing the slant. Buckle according to claim 1, wherein said stopping means comprises pins (4c) securely mounted on the guide housing (4) and holes (4d) formed in the push plates (2) so as to be engaged with the pins. Buckle according to claim 1, wherein each of said engaging projection (2a) of the push plates (2) is an engaging hook provided opposite to engaging hook of the other push plates. Buckle according to claim 1, wherein said push plates (19) are disposed in point symmetry with respect to a center of the housing (15). Buckle according to claim 1, wherein said engaging lug (23) of the bottom plate (18) has a conical head (23a) at a top thereof. Buckle according to one of claims 1 to 5, wherein the tongue (6) is rotatably mounted on the first end of the cover (1) by the pin (12) at a position adjacent to the guide housing (4) so as to be engaged with one of the adjusting holes of the band member (8).

Inventors: KASHIKIE JUNSUKE, TAGUCHI HIDEO, KASHIKIE, JUNSUKE, TAGUCHI, HIDEO, KASHIKIE, JUNSUKE, TANASHISEIZOSHO, TAGUCHI, HIDEO, TANASHISEIZOSHO
Applicants: CITIZEN WATCH CO LTD, CITIZEN WATCH CO., LTD.
Application year: 1994
Main classification: A44C5
IPC codes: A44C5